The other day I picked up two packs of Topps 2010 at Walmart, and ripped 'em in the parking lot. The packs were as random as I could get, one from the fallen detritus at the open bottom of the gravity loader, and one from the more-or-less in order stack inside (card searching at Wal Mart?).
At the bottom of both of them were a few, 3 or 4, base cards that the foil was off register. I didn't even notice I got doubles until I got home when I was checking my list.
Oddly (I guess, it sort of stands to reason, actually) three of the off register cards I needed- but in the other pack, I got two of them as doubles.
So in 2 packs, I got three f-up cards I need, but got doubles of two of them in the other pack I grabbed. At the time, I only need 20 or so cards from the base, so it is a kind of interesting occurrence.